Ventilation system

ABSTRACT

A ventilation system and a method for producing the ventilation system are provided. The ventilation system includes an air vent including an entangled core and a separation layer formed on a side of the entangled core. The entangled core includes air space. A method for producing the ventilation system includes bonding the entangled core to a surface of the separation layer to form an air vent.

This nonprovisional application claims the benefit of U.S. Provisional Application No. 62/168,311, filed May 29, 2015.

BACKGROUND

The function and health of a roof and attic space is tied to the amount of ventilation the space receives. Without proper ventilation, excessive heat and/or moisture can build up within the attic space. Excessive heat leads to increased demand on environmental cooling needs in warm climates, and can contribute to the premature deterioration of the roofing components, such as the waterproofing or shingles. Excessive moisture can promote the growth of mold within the space, and contribute to the premature deterioration of the internal roofing components such as the roof rafters and decking. The use of roof vents is thus promoted. Soffit vents can provide for an intake air source, and roof ridge vents can provide for air outlets. Should either vent become blocked, by insulation for instance, the ventilation path is severed. With the ever increasing emphasis on energy-efficient homes, the use of attic insulation and the amount of attic insulation is increasing. Some building codes now require roofs to provide a certain amount of R-value in addition to that provided by traditional insulation. The use of sprayed insulation, typically polyurethanes, polystyrenes, or polyisocyanates, particularly between the roof rafters, is becoming increasingly popular. Improper installation of insulation can lead to the blockage of the soffit by loose blown insulation, over-sprayed foam, or tightly packed batting.

For example, blockage often results from insulation having been pushed into the eaves and covering the vent openings, preventing air from getting into or out of the building through the openings. Blockage of the vents can also occur when paint is applied to the vents and the secondary surrounding structure without ensuring that the paint does not dry and block the vents.

A variety of methods, systems and products have been developed for attempting to maintain a ventilation space proximate to thermal insulation. However, such conventional methods and systems suffer from certain significant deficiencies.

For example, conventional rafter vents are generally short molded articles of foam or styrene having a “U”-shaped cross section. Because the bottom surface of the “U” is a solid, relatively imperforate surface and is usually stapled tightly to roof sheathing, it almost completely seals-off the insulation from the ventilation space. Because these vents are made of styrene foam plastic, they block the escape of heat via conduction from the insulation as the rafter vent itself is an insulating material. Many conventional rafter vents are designed to be used on the first lower section of the rafter to prevent horizontally-installed insulation from the blocking the soffit. However, the solid design of the vents often inhibits air flow.

Another drawback of conventional rafter vents is that they are supplied to a construction site in a nestled bundle. Frequently, they are delivered along with the lumber in four or eight foot long bundles. Because they are fragile, very light in weight, and easily broken, and usually sit on the construction site for a long period of time before being used, construction sites are often littered with pieces of these products. Once the bundle is opened and not carefully stored, wind can pick up the large, extremely light panels and scatter them causing litter on construction sites and the neighborhoods surrounding them.

Other conventional methods for supplying air to the attic include louvered vents or ridge vents located in the portion of the structure at or near the ridge of the roof, as well as gable vents and turbines located on the roof structure. Each of these approaches, however, does not provide optimal air ventilation in the attic. The louvered vents that are located near the top of the roof generally provide ventilation only to the top of the roof at the ridge line, and thus not to the entire attic. The turbines that are attached to the roof require both a hole in the shingles and the roof deck, thus increasing the chances of water penetration into the attic; furthermore, they require energy for operation.

Roof structures not providing adequate ventilation to the attic area are known to produce high temperatures in the attic during the summer months. This typically results in reduced shingle life and increased air conditioner usage, and associated costs.

SUMMARY

Disclosed herein are a ventilation system and a method for producing the ventilation system. The ventilation system includes an air vent including an entangled core and a separation layer. The entangled core includes air spaces for airflow. The separation layer is formed on a surface of the entangled core. The air vent may be installed between an interior surface of a building, such as a roof decking surface, and insulation. The air vent may extend from a soffit vent to a ridge vent between rafters. A method for producing the ventilation system includes bonding the entangled core to a surface of the separation layer to form the air vent.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A shows an embodiment of the ventilation system including an entangled core having a waffle structure and a radiant barrier.

FIG. 1B shows a zoomed in view of the ventilation system of FIG. 1A.

FIG. 2A shows an embodiment of the ventilation system including an entangled core having a pyramid structure and a radiant barrier installed between two rafters.

FIG. 2B shows a zoomed in view of the ventilation system of FIG. 2A.

FIG. 3 shows an embodiment of the entangled core with a pyramid structure.

DETAILED DESCRIPTION OF EMBODIMENTS

Disclosed herein is a roof ventilation system including an air vent containing an entangled core and a radiant barrier bonded to the entangled core. The radiant barrier includes a reflective surface that as infrared reflectivity. The entangled core includes air spaces for air flow through the ventilation system. The ventilation system may include, for example, a soffit vent, a roof ridge vent, and a rafter vent connecting the soffit and the ridge. All vents may be comprised of entangled polymeric filaments combined with various fleeces, films, and foils. The soffit vent may be an air intake source and the roof ridge vent may provide for an air outlet. The rafter vent is designed to be installed between the roof rafters continuously from the soffit to the ridge, providing a clear ventilation path between the two vents. The ventilation system prevents blockage of the free air path by preventing insulation from blocking the soffit vent intake, blocking the air path between the rafters, and blocking the air outlet at the roof ridge. The ventilation system prevents the blockage of a clear air path by batting, blown, or sprayed insulation either on the floor of the attic along the roof edges or between the roof rafters. The ventilation system is a passive device, requiring no external blowers, fans, or other forced air implements to achieve ventilation, but such devices may be included to further improve ventilation efficiency.

The ventilation system may maintain a ventilation space proximate to insulation material, such as thermal insulation. The ventilation system disclosed herein is suitable for use in roofs and ceilings where ventilation must be maintained to expel heat and moisture from thermal insulation. The ventilation system is suitable for any application involving building surfaces where it is desirable to maintain ventilation space. For example, the ventilation system may be used in cathedral ceiling and roof structures.

A “cathedral” ceiling and roof structure refers to the construction practice of creating a sealed attic space. Such constructions are referred to as “cathedralized” because the insulation is placed between the roof rafters. This allows for the attic space to be conditioned, offering energy savings when HVAC equipment is placed in the space. The practice reduces the energy losses from equipment and ductwork leakages. The current ventilation system supports and improves this type of construction practice by allowing the installation of rafter insulation while still providing for a ventilated space.

The present ventilation system allows thermal insulation to ventilate over its entire area. The ventilation system is a durable rolled good with a thickness of about 0.1 to about 5 inches, for example about 0.25 to about 3 inches, about 0.5 to about 2 inches, or about 0.75 to about 1.5 inches. The ventilation system can be stored on a construction site with almost no danger of damage, deterioration, or wind disbursement, as the configuration of the system permits wind to blow through the system without moving it. The materials used in the device are tough and able to resist abuse and UV degradation. In addition, the ventilation system or its components may be delivered to a jobsite in a roll that can be cut to the length required. Accurate and positive regulation of the insulation vent space enable a smaller recommended depth, allowing greater R values to be used, thus resulting in a savings in construction cost.

The ventilation system includes at least an entangled core made of a thermoplastic material. The entangled core may be affixed to a barrier or separation layer, which separates the air space created by the entangled core and the installed insulation or open attic space. The separation layer may also act as a filter, particularly for blown or sprayed insulation systems, and it can also provide an active component such as a radiant barrier. The radiant barrier contributes to reducing the overall heat flux through a roof, lowering the amount of heat energy passing through the roof into the living space.

The entangled core has a three-dimensional patterned structure. The entangled core may be made of any thermoplastic material. In some embodiments, the thermoplastic material of the entangled core is able to withstand roof temperatures of about 65 to about 100° C. The thermoplastic material may be, for example, a polyester, polyolefin, or nylon. Exemplary materials for the entangled core include polypropylene, nylon 6 (or polyamide 6), polylactic acid, polycaprolactone, polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, polyethylene naphthalate, vectran, high density polyethylene, and blends or copolymers thereof.

The entangled core is shown as 11 in FIGS. 1A-3. The polymer structure of the entangled core 11 is formed by extrusion into a three-dimensional structure having a patterned configuration. For example, the entangled core 11 may have a patterned configuration including pyramids, cones, waffles, cylinders, and the like. For example, the entangled core 11 has a waffle structure in FIGS. 1A and 1B and has a pyramid structure in FIGS. 2A, 2B, and 3. The patterned structure of the entangled core 11 creates an air space 13. The open air space 13 may make up about 80 to about 99% of the entangled core, for example, about 85 to about 99%, about 90 to about 99%, or about 95 to about 98% of the entangled core is open air space. The entangled core structure 11 may have a thickness in a range of from, for example, about 0.1 inches (12.5 mm) to about 5.0 inches (75 mm) in thickness, such as about 0.25 to about 4.0 inches, about 0.5 to about 3.0 inches, or about 0.75 to about 1.5 inches. The entangled core may have a basis weight in a range of from, for example, about 5 to about 25 ounces per square yard (osy), about 10 to about 20 osy, or about 12 to about 18 osy. Preferably, the entangled core has a thickness of about 1.5 inches (38 mm) with a basis weight of about 15 osy. The entangled structure of the entangled core 11 reduces thermal heat flux through the structure/building by convection.

The embodiment illustrated in FIGS. 1A and 1B includes a three-dimensional entangled filament structure (an entangled core 11) 20 mm thick thermally bonded to a coated aluminum foil (radiant barrier 12). The three-dimensional core 11 is comprised of thermally bonded polypropylene monofilaments ranging from about 500 to about 600 μm in diameter. The core 11 is configured in what is known as a “waffle” pattern, characterized by individual domes of filaments separated by intersecting lanes that promote air flow in both directions (air spaces 13). The overall weight of the core 11 is about 25 ounces per square yard. The core 11 is bonded to an aluminum foil 12 coated on one side with a polyolefin-compatible proprietary coating that can be thermally bonded to the polypropylene core. The reflective surface 12 a of the radiant barrier 12 bonded to the core 11 exhibits radiant barrier properties as defined by ASTM C1371, with a measured emissivity value of 0.08. The outer surface of the aluminum foil (radiant barrier) 12 is fully coated with polyester to prevent oxidation, and thus deterioration of the aluminum foil 12. The reflective surface 12 a of the radiant barrier 12 faces inward toward the air gap 13 provided by the three-dimensional core 11, so that as it is installed, the thermal radiation is reflected away from the living space and back into the air gap 13.

In an embodiment illustrated by FIGS. 1A and 1B, the ventilation system 10 includes an entangled core 11 having a waffle structure and a radiant barrier 12. The ventilation system 10 is adjacent to a roofing deck 14. The roofing deck may be made of, for example, particle board or plywood. As shown in FIG. 1B, the waffle structure of the entangled core 11 creates an air space 13 that is separated from any installed insulation or open attic space (not shown) by the radiant barrier 12. The radiant barrier 12 may include a carrier film 12 b with a reflective coating or laminated surface 12 a. In this embodiment, the radiant barrier 12 acts as a separation layer separating the air space 13 created by the entangled core 11 from the insulation or open attic space. The ventilation system 10 may include a separation layer on a side of the radiant barrier opposing the side of the radiant barrier 12 attached to the entangled core 11. The separation layer may be between the radiant barrier and the insulation or open attic space.

The radiant barrier 12 may include a carrier film with a reflective coating or laminated surface 12 a. The radiant barrier 12 is attached to an inner face 15 a of the rafters 15. The radiant barrier 12 is configured to reflect radiation so it does not conduct heat into the structure/building. The reflected radiation (heat) is transferred through the air space 13 of the entangled core 11 and carried out by the air flow to an output vent, for example, a ridge vent. The radiant barrier 12 may be attached to the entangled core 11 via an adhesive or thermal bond. The radiant barrier 12 may include a metallic foil, aluminum foil, metallic fabric, aluminized sheet, metal sheet, metallic film, aluminum paint, aluminum coating, reflective coating, or reflective film. In some embodiments, the radiant barrier 12 may be a metalized polymer film, for example, a metalized polyester, metalized polyethylene, metalized polypropylene, metalized polyethylene terephthalate, or metalized nylon film, such as a metalized nylon 6 film.

The radiant barrier 12 may be a film having a thickness in a range of from about 10 μm to about 500 μm, such as, about 13 μm to about 250 μm, about 25 μm to about 200 μm, or about 50 μm to about 150 μm. In one embodiment, the radiant barrier 12 may be about 100 μm thick. The radiant barrier 12 may be comprised of a carrier film 12 b with a reflective coating or laminated surface 12 a exhibiting high infrared reflectivity. The coating may include a low emittance coating that can lower the thermal emissivity of the surface of the radiant barrier 12. The coating may include paints, plating, resins, sheets, laminates, films, vacuum deposited metals, and other coatings that increase the radiant energy reflectance of the surface and reduce the radiant energy emittance of the surface.

The reflective coating or laminate surface 12 a may include a reflective metal, for example, aluminum, gold, silver, chromium, copper, nickel, zinc, and alloys thereof. The radiant barrier 12 may exhibit an emissivity of less than or equal to about 0.10 per ASTM C-1371, such as about 0.01 to about 0.10, about 0.05 to about 0.10, or about 0.08 to about 0.10. The radiant barrier 12 may have a reflectivity that is greater than about 0.9, such as greater than 1 or greater than 1.5.

The carrier film may be coated on one or both sides to protect the reflective surface and to provide a bond layer to the entangled mesh core. The reflective surface 12 a is only provided on the side of the carrier film that faces the entangled core 11. The radiant barrier blocks radiation from entering the room or attic space by reflecting radiation into the air space 13 between the radiant barrier and the entangled core 11. The radiation may then exit the ventilation system 10 with the airflow through the air spaces 13 of the entangled core via an output vent, such as a ridge vent.

In some embodiments, the reflective surface 12 a of the radiant barrier 12 may be functionalized to be compatible with the entangled core. The reflective surface 12 a of the radiant barrier 12 may include a polymer coating made of a polymer material similar to that of the entangled core 11. Such a configuration allows the radiant layer 12 and the entangled core 11 to be thermally bonded together without the need for an adhesive. For example, if the entangled core is made of polypropylene, then the reflective surface 12 may include polypropylene such that the radiant barrier 12 may be thermally bonded to the entangled core 11 without the need for additional adhesive. If the entangled core 11 is made of nylon 6, for example, then the reflective surface 12 a may include nylon 6 such that the radiant barrier 12 may be thermally bonded to the entangled core 11 without the need for adhesive. This enables the radiant properties of the reflective surface 12 a to be maintained. Alternatively, the radiant barrier 12 may be bonded to the entangled core 11 with an adhesive, such as a hot melt adhesive or other chemical adhesive. The radiant barrier 12 may also be laminated to other substrates, such as a paper or nonwoven support, protector, or grab layer for sprayed or blown insulation. For example, the radiant barrier 12 may be laminated to a separation layer 16.

Another embodiment, illustrated in FIGS. 2A and 2B, includes a three-dimensional entangled filament structure (entangled core 11) 25 mm thick thermally bonded to a nonwoven textile (separation layer 16). The three-dimensional core 11 is comprised of thermally bonded polyamide 6 monofilaments ranging from about 500 to about 600 μm in diameter. The core 11 is configured in what is known as a “pyramid” pattern, characterized by individual pyramids of filaments separated by offset intersecting lanes that promote air flow in both directions (air spaces 13). The overall weight of the core 11 is about 15 ounces per square yard. The core 11 is bonded to a nonwoven 16 known commercially as Colback® available from Bonar Inc. The nonwoven separation layer 16 is a thermally-bonded structure comprised of sheath-core bicomponent yarns. The sheath of the yarns is polyamide 6 (PA6), making the nonwoven 16 thermally compatible with the PA6 three-dimensional core. The nonwoven 16 has a basis weight of about 100 gram per square meter.

In an embodiment illustrated by FIGS. 2A and 2B, the ventilation system 10 includes an entangled core 11 having a pyramid structure and a separation layer 16 between two rafters 15. As shown in FIG. 2B, the entangled core 11 having a pyramid structure creates an air space 13 that is separated from any installed insulation or open attic space (not shown) by the separation layer 16. The separation layer 16 may be thermally or adhesively bonded to the entangled core 11. For example, hot melt glue or other chemical adhesives or attachment devices may be used to attach the separation layer to the entangled core 11. The separation layer 16 may be a nonwoven textile, film, kraft paper, or a combination thereof. For example, the separation layer 16 may be needled felt, a spunbond material, or a meltblown material. The separation layer 16 may have a basis weight in a range of from about 50 grams per square meter (gsm) to about 180 gsm, for example, about 70 to about 130 gsm, about 80 to about 120 gsm, or about 90 to about 110 gsm.

The separation layer 16 provides separation between the entangled core 11 and the attic space. The separation layer 16 prevents blown or sprayed insulation from being transported into the entangled monofilament structure of the entangled core 11 during installation of the insulation. The separation layer 16 provides support for the sprayed foam insulation after it has cured. The separation layer 16 also strengthens the entangled monofilament structure by providing tie points for the entangled monofilament structure, increasing the structural integrity of the system and minimizing potential movement, because the separation layer 16 is bonded to the entangled core 11. The overall structure has sufficient compression resistance to prevent occlusion of the air space 13 during installation of insulation. The separation layer 16 may extend past the edges of the entangled core 11 to provide easy installation through the use of mechanical fasteners such as nails, staples, or adhesives. The structure is sized to fit tightly between roof rafters 15, with the extended flaps of the separation layer 16 flush against the inner face 15 a of the rafter in position for mechanical fastening to the rafter face 15 a.

The separation layer 16 may be functionalized to be compatible with the entangled core 11. The separation layer 16 may include a polymer material similar to that of the entangled core 11. Such a configuration allows the separation layer 16 and the entangled core 11 to be thermally bonded together without the need for an adhesive. For example, if the entangled core is made of polypropylene, then the separation layer 16 may include polypropylene such that the separation layer 16 may be thermally bonded to the entangled core 11 without the need for additional adhesive. If the entangled core 11 is made of nylon 6, for example, then the separation layer 16 may include nylon 6 such that the separation layer 16 may be thermally bonded to the entangled core 11 without the need for adhesive. Alternatively, the separation layer 16 may be bonded to the entangled core 11 with an adhesive, such as a hot melt adhesive or other chemical adhesive.

The external layer of some roof structures may be a material with relatively high heat conductivity compared to other materials. Metal roofs and asphalt shingles are examples of external layers that have more heat conductivity than wood shingles or ceramic tiles. Because of this relatively high heat conductivity, such external layers can transmit a large amount of heat to the underlying substrate, potentially causing long-term damage to the substrate, and/or causing thermal inefficiency of the building as a whole.

To reduce such transmission of heat, the present ventilation system additionally provides a thermal barrier in a building roof structure. The entangled filaments comprising the core of the rafter air vent form a thermal barrier by first reducing the physical contact between the external roof layer and the inner space of the building structure. Secondly, the creation of the ventilated air space reduces the thermal heat flux through the structure by convection. The addition of a radiant barrier 12 to the vent completes the thermal resistance package by providing a barrier to radiated energy.

The ventilation system 10 disclosed herein may be installed proximate to insulation material. For example, the ventilation system 10 may be installed between building sheathing and the insulation material to permit ventilation of the insulation. The ventilation system 10 may be interposed between exposed thermal insulation material and the underside of roof sheathing or the underside of an attic floor. However, the ventilation system 10 may be used wherever it is desired to maintain a ventilation space, or similar voids for other purposes, including walls of structures, interior acoustically dampened partitions, or alternative applications such as automotive, marine, aviation, or aeronautical applications.

A method is also provided herein for producing and maintaining a ventilation system. The method includes placing the ventilation system 10 including at least the entangled core 11 and the radiant barrier 12 proximate to a roofing deck such that the ventilation system 10 is interposed between the roofing deck and insulation material or open attic space. The ventilation system may be placed between rafters running from a soffit vent to a ridge roof vent. The air spaces 13 in the entangled core 11 form uninterrupted air flow paths between a soffit vent and a ridge vent. The radiant barrier 12 reflects solar radiation into the air spaces 13 of the entangled core such that the reflected heat can be carried out by the air flow.

Although a few example embodiments have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the example embodiments without materially departing from the ventilation system. Accordingly, all such modifications are intended to be included within the scope of this disclosure as defined in the following claims. In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents, but also equivalent structures. Thus, although a nail and a screw may not be structural equivalents in that a nail employs a cylindrical surface to secure wooden parts together, whereas a screw employs a helical surface, in the environment of fastening wooden parts, a nail and a screw may be equivalent structures. It is the express intention of the applicant not to invoke 35 U.S.C. §112, paragraph 6 for any limitations of any of the claims herein, except for those in which the claim expressly uses the words ‘means for’ together with an associated function. 

What is claimed is:
 1. A ventilation system comprising an air vent comprising: an entangled core comprising air spaces; and a separation layer formed on a side of the entangled core.
 2. The ventilation system according to claim 1, wherein the entangled core has a thickness of about 0.5 to about 5 inches.
 3. The ventilation system according to claim 1, wherein the entangled core comprises a thermoplastic material selected from the group consisting of a nylon, polyester, and polyolefin.
 4. The ventilation system according to claim 3, wherein the thermoplastic material is selected from the group consisting of polypropylene and nylon
 6. 5. The ventilation system according to claim 1, wherein the separation layer is thermally compatible with the entangled core.
 6. The ventilation system according to claim 1, wherein the separation layer is selected from the group consisting of a nonwoven textile, film, kraft paper, needled felt, spunbond material, meltblown material, or a combination thereof.
 7. The ventilation system according to claim 1, further comprising a radiant barrier comprising a reflective surface having infrared reflectivity, wherein the reflective surface of the radiant barrier is bonded to the entangled core.
 8. The ventilation system according to claim 7, wherein the reflective surface of the radiant barrier has an emissivity of 0.1 or less.
 9. The ventilation system according to claim 7, wherein the reflective surface of the radiant barrier has a reflectance of 0.6 or more.
 10. The ventilation system according to claim 7, wherein the air vent further comprises a separation layer bonded to a side of the radiant barrier that opposes the reflective surface bonded to the entangled core.
 11. The ventilation system according to claim 7, wherein the reflective surface of the radiant barrier is thermally bonded to the entangled core.
 12. The ventilation system according to claim 7, wherein the radiant barrier comprises the thermoplastic material of the entangled core.
 13. The ventilation system according to claim 7, wherein the reflective surface of the radiant barrier comprises a metal selected from the group consisting of aluminum, gold, silver, iron, chromium, nickel, copper, and alloys thereof.
 14. The ventilation system according to claim 1, wherein: the air vent is installed between an interior surface of a building and insulation; and the air vent extends from a soffit vent to a ridge vent.
 15. The ventilation system according to claim 14, wherein the air vent is installed between rafters.
 16. The ventilation system according to claim 1, wherein the entangled core has a three-dimensional structure selected from the group consisting of a waffle structure, a pyramid structure, a cone structure, and a cylinder structure.
 17. The ventilation system according to claim 1, wherein the air spaces make up 90 to 99% of the entangled core.
 18. A method for producing the ventilation system according to claim 1, comprising banding the entangled core to a surface of the separation layer to form an air vent.
 19. The method according to claim 18, further comprising installing the air vent between an interior surface of a building and insulation.
 20. The method according to claim 18, wherein the air vent is installed between rafters and extends from a soffit vent to a ridge vent. 